Telegraphy.



Patented AprQ 2, IBM.

D. MURRAY.

TELEGRAPHY.

[Applicafio'n filed Jan. 17I 1901.)

2 Sheets-Sheet I.

(No Model.)

INVENTOR:

My Aftol' ey No. 670,964. Patentad- Apr. 2, mm.

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TELEGBAPI'IY.

(Applicatifin filed Jim. 11. 1901.) (No Model.) 2 Sheets-Shoot 2.

WITNESSES TN: NORRIS Pain; cu. vac-mums" wAsmNuToM. D. c.-

llurrnu STATES PATENT @rrrcn.

DONALD MURRAY, OF NEW YORK, N. Y., ASSIGNOR TO POSTAL TELEGRAPH- CABLE COMPANY, OF SAME PLACE.

TELEGRAPHY.

SPECIFICATION forming part of Letters Patent No. 670,964, dated April 2, 1901.

Application filed January 17, 1901. b'erial No. 43.571. (No model.)

To (tZZ whom it may concern.-

Be it known that I, DONALD li/IURRAY, a subject of the Queen of Great Britain, residing in the city of New York, county and State of New York, have made certain new and useful Improvements in Telegraphy, of which the following is a specification.

This invention is an improvement upon the well-known Wheatstone transmitter em- 1o ployed in automatic telegraphy and certain modifications of my page-printing telegraph.

The object of the invention is to adapt the transmitter to the requirements of my printing-telegraph system shown and described in United States Letters Patent No. 653,936, dated July 17, 1900.

The improvement consists in locating the prickers or projecting pins designed to pass through holes in the perforated tape side by side and moving them automatically in unison or simultaneously instead of alternately, as in the Wheatstone case. By this means I am enabled to transmit current impulses of unit duration or any odd or even multiple thereof, whereas the Wheatstone transmitter has capacity for transmitting unit impulses and any odd-number multiple thereof only. In said patent the transmitting apparatus shown and described consists of metal brushes making electrical contact on the periphery of a revolving wheel through perforations in a paper tape. According to my improvement I employ a WVheatstone transmitter further modified in the manner about to be described and driven at a uniform rate by a suitable motor. Wheatstone transmitters are operated by clockwork with a fanregulator. This is inconvenient, as the clockwork requires frequent winding. I prefer to employ a modification of an electric pendu lum-motor generally known as the La Cour phonic wheel. This has the advantage of running at a very uniform rate which is practically independent of the amount of current.-

by the ordinary Wheatstone transmitter and by my improved modification of it.

In Fig. l, a is a vibrator which operates the motor 1), which in turn drives the modified \Vheatstone transmitting apparatus 0, thereby sending current impulses over the main line d. The vibrating reed 7 of the vibrator a is driven by the two electromagnets 1 and 2, each operated by a local circuit alternately under the control of the break-points 3 and 4. These operate on the familiar buzzer principle, each magnet breaking its own circuit on the opposite side of the reed. The current to drive the vibrator and motor comes from any suitable source, as 70, along the wire 5, vise 6, reed 7, contact-spring 3, wire 8, vibrator-magnet 1, wire 9, motor-magnet 10, and wires 11 and 1.2 back to the source of current. This energizes the magnet 1, which attracts the reed 7, breaking the contact with spring 3 and making contact with spring 4. The current then goes from the reed 7 by the contact-spring 4 through wire 14, vibratormagnet 2, wire 15, motormagnet 16, and wires 17 and 12 back to the source of current. The result is that the motor-magnets l0 and 16 receive alternate impulses, the rate being determined by the rate of vibration of the reed.

This rate can be varied by shifting or varying the weight 18. The toothed iron armature 19 is started by being spun around by hand, and the alternating impulses in the motor-magnets then keep it revolving at an extremely uniform rate. By suitable gearing 20 and 21 this armature operates the small crank 22 and pitman-rod 23, which gives an oscillating motion to the rod 24, fixed in the end of the crank 25. The bell-crank levers 26 and 27, pivoted at 28 and 29, press up against the rod 24. under the action of the spring 30. The oscillations of the rod 24: are thus communicated by means of the levers 26 and 27 to the rods 31 and 32. These simultaneously strike the top and bottom of the contact-bar33,which 5 is pivoted at 34 and is free to oscillate between the contact-points 35 and 36. The rods 31 and 32, striking the contact-bar 33 simultaneously, neutralize each others action and no definite result follows. This is what hap-- 10o pens when the transmitter is running empty or without perforated tape.

Under the control of the paper tape 37 the action is as follows: The armature-shaft 38 carries at its extremity a small star-wheel 39, which feeds the tape along at a uniform rate by engaging with the central line of perforations 40. The fluted roller 41 serves to keep the tape engaged with the star-wheel 39 and to hold the tape down against the upward thrust of the prickers 42 and 43. On each side of the central line of perforations in the tape a series of holes 71 and 72 is punched to govern the occurrence and duration of the current impulses. These holes are so arranged that two are never in line with one another across the tape. The consequence is that only one of the two prickers 42 and 43, which are intermittently thrust against the lower surface of the tape by the spring and the oscillating cranks 26 and 27, can enter a perforation in the tape at one time. Let us assume that pricker 43 enters a perforation in the tape, pricker 42 being therefore stopped in its upward progress by a non-perforated portion of the tape. Pricker 43 passing through a perforation, the crank-lever 27 will rise under the influence of the spring 30, and rod 31 will be thrust against the top of the contact-bar 33, which will be tilted over to the contact 36, where it will remain until it is tilted back to contact-point by a corresponding action of rod 32 when pricker 42 enters a hole in the tape. The bar 33 therefore remains resting against contact-point 35 or 36 until thrust over to the opposite contact-point as the result of one or other of the prickers 42 43 entering a hole in the tape. The result is that current flows for definite intervals from either the positive or negative batteries 44 or 45 by way of the contacts 35 or 36, contact-bar 33, and the main line d to the receiving-station. By omitting one of the hatteriessay 44-the apparatus will transmit simple makes and breaks of current instead of reversals.

In the ordinary Wheatstone transmitter the crank 25 is so arranged that it oscillates the bell-crank levers 26 and 27 alternately instead of simultaneously, as is done in the improved arrangement just described. The result is that in the ordinary Wheatstone transmitter when it is running empty the rods 31 and 32 strike the bar 33 alternately. Consequently it oscillates regularly between the contacts 35 and 36, sending short positive and negative impulses alternately to the main line or makes and breaks, if only one battery is employed. The effect of the perforated tape in the ordinary Wheatstone arrangement is to suppress one or more of these alternations. The ordinary Wheatstone transmitter is, in fact, a small alternating-current generator and the signals are transmitted by suppressing one or more of the half-waves of a complete alternation. This is shown clearly in Fig. 3. Line 47 shows the alternating-current impulses generated by an ordinary Vheatstone transmitter running empty with the corresponding dot-signals which these currents record. Line 48 shows that the only signals that it is possible to build up out of this alternating current are signals or spaces of one, three, five, seven, 850., units duration-that is to say, odd-number multiples of the unit or dot current. In the page-printing system of telegraphy described in my said Patent No. 653,936 it is necessary to be able to transmit current impulses or spaces of one, two, three, four, five, or more units durationthat is to say, even-number, as well as oddnumber, multiples of units. This is shown in line 49 ofFig. 3. This arrangement of signals is obtained, as already explained, by getting rid of the alternating character of the heatstone transmitter by making the prickers 42 and 43 and the bell-crank levers 26 and 27 reciprocate together instead of alternately. Under the arrangement shown in Fig. 1 a perforation on the right-hand side of the tape starts a current-signal, and it continues untiL it is stopped by a perforation on the left-hand side of' the tape, and vice versa. Any integral multiple of the unit-current or unit-space can thus be transmitted.

The current impulses generated as de scribed pass over the main line d through the relays e and f, Fig. 2, at the receiving-station to ground. The action of the receiving mechanism is identical with that already fully described in my said Patent No. 653,936. Briefly, the action of the receiving apparatus there described is a follows: 50 is an electromagnet which operates the p unching-lever 51, which depresses the punch 52, thereby perforating the paper tape 53. 54 is an electromagnet which feeds the tape forward step by step by operating an anchor-escapement 55 and motor-driven starwheel 56. This punching and spacing mechanism is controlled by the vibrator g, consisting of the Vibrating reed 57, driven by the electromagnet 58 on the usual buzzer principle, breaking its own circuit at the contact-spring 59. As the reed vibrates it makes alternate contacts with the contact-springs 60 and 61. makes momentary contact with spring 60, the circuit of the spacing-magnet 54 is closed and the paper tape 53 is advanced a step by means of the anchor-escapement 55 and the star-wheel 56. When the reed 57 makes con tact with the spring 61, the punching-magnet 50 is energized and a hole is punched in the tape, provided the tongue 62 of the relay 8 is closed on its front contact 63. The main-line signals thus control the operation of the punching-magnet 50. In order that the reed 57 may vibrate in unison with the rate of the arriving current-signals, a governing-relay f -is provided. The back and front contacts of this relay 64 and 65 are electrically united, so

that the relay-tongue 66 only momentarily breaks the local circuit of the Vibrator-magnet 58 in crossing over at the beginning and end of the main-line signals. As the mainline signals arrive at a uniform rate and as they consist of unit currents and spaces or When the reed multiples thereof, the relay-tongue 66 breaks the vibrator-circuit at uniform unit intervals or multiples thereof. There are thus two break-points in the same circuitnamely, that controlled by the relay-tongue 66 and that of spring 59. If the two breaks continuously occur together, then the magnet 58 gets full impulses of current. If, on the other hand, owing to a variation between the rate of vibration of the reed 57 and the rate of the arriving signals the two breaks occur more or less alternately-that is to say, if they get out of step with one anotherthen less current gets through the vibrator-magnet circuit, the impulses are clipped, and the amplitude of vibration of the reed 57 is reduced. Resilient limiting-stops 67 and 68 are provided. The reed 57 when vibrating between limiting-stops graduated in the manner shown varies its rate of vibration in ac cordance with the amount of current traversing the circuit of the vibrator-magnet 58. The two interfering break-points in the same circuit control the amount of current, and so control the rate of vibration of the reed and keep it in substantial harmony with the rate of the arriving current impulses.

' What I claim, and desire to secure by Letters Patent, is

1. In an automatic transmitter the combination of a suitable tape having two parallel lines of perforations arranged in alternation, means for uniformly advancing said tape, a circuit-closing device or switch and means for causing said switch to throw upon the line current impulses of unit duration or integral multiples thereof, either odd or even, consisting of two coincidently noving rods, located in line with said perforations respectively, and a motor-driven actuating device for reciprocating said rods coincidently within limits established by said perforated tape.

2. In a telegraph system a main line, an automatic transmitter, arranged to direct upon said line current impulses of unit duration or integral multiples thereof, a phonic wheel propelled by electromagnets for driving said transmitter, a vibrating reed and a local circuit supplying current impulses to said magnets, an electromagnetic tape-perforating device at the receiving station and means for maintaining unison between said transmitter and perforator.

DONALD MURRAY.

Witnesses:

O. E. DAVIDSON, A. M. DONLEVY. 

